thanks to Ryan R I have a backported version of the mce keyboard driver from ir-core in Linux 3.1.  I've packaged this for Ubuntu Natty and Oneiric here:

add this repository (ppa:jon-hedgerows/lirc-mod-mce) and then install ir-mce-kbd-decoder-dkms

The keyboard should then work out of the box.  If you have lirc installed, you may need to check that lirc hasn't switched of in-kernel decoding of rc-5 and rc-6 protocols.

Linux 3.1 (which should be in Ubuntu Precise in April 2012) includes native support the the mce keyboard, so mod-mce has reached the end of the line, and no future versions of Ubuntu should need backports to support the keyboard.